The formation, of a lubrication film on the surface of various types of substrates by coating the surface of the substrate with a resin capable of being cured by high energy beams such as ultraviolet radiation or the like, and irradiating the coated substrate with the high energy beams, is known. Various proposals have been made previously for coating compositions for lubrication film to form a lubrication film in this manner.
A composition for forming a lubrication film including a UV curable resin is proposed in Patent Document 1. Finely powdered polytetrafluoroethylene is further blended in this composition as a friction reducing agent. According to this composition, a finely powdered polytetrafluoroethylene (i.e. fluoro resin fine particles) is included in this composition, and thus it is possible to maintain good sliding characteristics over a long time interval, and it is possible to lower the coefficient of friction during sliding.
Patent Documents 2 and 3 disclose high energy beam-curable coating compositions that include 100 parts by mass of a high energy beam-curable polymerizable monomer (A), 0.01 to 10 parts by mass of a lubricating agent (B), and 0.1 to 10 parts by mass of a high energy beam polymerization initiator (C). By using this composition, these documents teach that it is possible to form a coating that has excellent wear resistance, surface lubrication, and excellent transparency over a long time interval.
Patent Document 4 discloses a coating composition for a film formed by blending 10 to 100 parts by weight of a silicone rubber spherical fine powder (average particle diameter of 1 to 20 μm, JIS A hardness of 60 to 80) per 100 parts by weight of a curable silicone polymer. According to this composition, a film can be formed that has good visual appearance (i.e. mat), and has excellent lubrication ability, wear resistance, and coating surface scratch resistance.